diff --git a/compctld.c b/compctld.c
index dc48c756151abb27bcd1694ab13feef9621d63e9..6ac733f66cf6c7571a2e0d63c18336c482847b42 100644
--- a/compctld.c
+++ b/compctld.c
@@ -180,7 +180,7 @@ sockerror:
 		struct cmsghdr *cmsg;
 		cmsg = CMSG_FIRSTHDR(&msg);
 		if (cmsg == NULL || cmsg->cmsg_len != CMSG_LEN(sizeof(*cred))) {
-			syslog(LOG_INFO, "want %lu", CMSG_LEN(sizeof(*cred)));
+			syslog(LOG_INFO, "want %zu", CMSG_LEN(sizeof(*cred)));
 			errmsg = "cmsg";
 			goto sockerror;
 		}